Teachers among huge spike in cases

Two Sydney school teachers and an employee at a prison hospital are among recent coronavirus cases in NSW as the state's number of confirmed infections reaches 1791.

NSW Health Minister Brad Hazzard on Sunday said 24 people were in intensive care but no new deaths had been reported, with the state toll remaining at eight.

Cases without a known source of transmission had on Sunday reached 207.

New cases include two teachers and a student from Normanhurst West Public School and a staff member at the hospital inside Long Bay prison.

The number of Australian cases from the Ruby Princess cruise ship has spiked to 215 - with 189 of those cases diagnosed in NSW - after passengers disembarked in Sydney without adequate checks.

Mr Hazzard again urged people to follow guidelines to self-isolate and take precautions around social distancing, saying the whole word was facing "an unseen enemy that doesn't have borders".

NSW Premier Gladys Berejiklian said the state "will move quickly to enforce additional restrictions on gatherings to slow COVID-19" after Prime Minister Scott Morrison on Sunday night advised of a two-person limit for indoor and outdoor public gatherings.

The gathering limit won't apply to members of the same household or family units, Mr Morrison said.

It will be up to the individual states and territories whether it is strictly enforced by police.